Composite material typically include a matrix of orientated fibrous material (such as graphite, boron, glass or polyimides) impregnated with an epoxy, polymeric, phenolic or similar resinous organic, material. The strength/weight ratio of composite materials provides a significant advantage over conventional materials in a variety of applications.
One type of composite material manufacturing utilizes composite materials that are formed by impregnating woven fibrous cloth, yarn, or fiber tow with a predetermined amount of organic resin, and staging and drying the organic resin to form a partially cured ("tacky") composite material (prepreg), which is subsequently packaged in protective film. Prepreg composite material in the tacky condition is handled and processed in all the operations comprising the pre-cure fabrication phase. Another composite material manufacturing process utilizes only the orientated fibrous material matrix in the pre-cure fabrication phase. Organic resin is injected into the orientated fibrous material matrix immediately prior to the initiation of the cure fabrication phase. Prepreg and wet resin manufacturing systems or processes each have distinct advantages and disadvantages in the manufacture of composite articles.
Composite articles may be fabricated in either process utilizing a plurality of stacked, fiber plies which vary in size, shape and fiber matrix orientation. The pre-cure fabrication phase in forming composite articles typically involves several independent operations such as cutting of composite material into individual composite plies, each having the requisite shape, stacking or placing the cut composite plies in the mold cavity in accordance with the desired fiber orientation (layup), and forming each stack of composite plies over a mold surface contour to ensure proper compaction (debulking) of stacked composite plies, e.g., without wrinkling, during curing.
Prior art pre-cure fabrication operations are typically highly labor intensive and time consuming (and thus costly), requiring manual handling of the composite material/plies during the operations of the pre-cure fabrication phase. For example, the composite material workpiece or roll generally must be hand-placed into position, cut along guide lines to the desired shape or pattern (configuration), and hand transported to a molding station or cell where the cut composite ply is hand laid or stacked in a mold cavity. Hand pressure is utilized to conform the stacked composite ply to the mold surface contour and to stack successive composite plies in combination with previously stacked plies.
However, automated systems are very expensive, and therefore use thereof must be maximized to justify the cost. Additionally, some automated processes do not work well enough to alleviate the need of operators who may be required to verify automated operation (rather than performing hand operation).